Cognitive load and task condition in event- and time-based prospective memory: an experimental investigation

Prospective memory is memory for the realization of delayed intention. Researchers distinguish 2 kinds of prospective memory: event- and time-based (G. O. Einstein & M. A. McDaniel, 1990). Taking that distinction into account, the present authors explored participants' comparative performance under event- and time-based tasks. In an experimental study of 80 participants, the authors investigated the roles of cognitive load and task condition in prospective memory. Cognitive load (low vs. high) and task condition (event- vs. time-based task) were the independent variables. Accuracy in prospective memory was the dependent variable. Results showed significant differential effects under event- and time-based tasks. However, the effect of cognitive load was more detrimental in time-based prospective memory. Results also revealed that time monitoring is critical in successful performance of time estimation and so in time-based prospective memory. Similarly, participants' better performance on the event-based prospective memory task showed that they acted on the basis of environment cues. Event-based prospective memory was environmentally cued; time-based prospective memory required self-initiation.     

意向保持间隔对时间性前瞻记忆的影响

通过两个实验来探讨意向保持间隔对时间性前瞻记忆的影响。实验一仅通过嵌入前瞻目标的背景任务来操纵保持间隔,实验二通过在背景任务之前加入不同时长的填充任务来改变意向保持间隔。结果发现,(1)背景任务中的保持间隔越长,前瞻记忆成绩越差;(2)背景任务中的保持间隔和填充任务的时长对前瞻记忆的影响存在交互作用。成绩最好的为15min-2min组,最差的为15min-15min组。结果表明,背景任务和填充任务阶段对于个体保持前瞻意向可能有不同的功能。     

Time-based prospective remembering: Interference and facilitation in a dual task

The aim of this study was to analyse prospective memory behaviour when people have to fulfil two different intentions whose retention intervals partially overlapped. More specifically, the purpose of the study was to explore the effects of a secondary PM task (either time-based or event-based) on performance of a main time-based PM task. Four embedded conditions were tested: two event-based ones and two time-based ones. The time- and event-based interpolated tasks differed in how closely their target time was to the 20-minute response required by the main time-based task (16th and 19th min., respectively). The results indicated that when a main time-based prospective memory task shares a portion of the retention interval with a second time-based prospective task, this overlapping facilitated performance on the main task. However, the interpolated tasks appeared to be affected by the moment in which they were administered during the execution of the main time-based task. More specifically, a decrease in the interpolated task performance was observed when this was time-based and had to be executed very closely to the target time of the main task. On the contrary, when the two tasks were different (event-based vs. time-based), there was neither interference, nor facilitation.     

情绪刺激对前瞻记忆的影响

使用情绪图片作为背景任务刺激,通过两个实验来考察积极情绪和消极情绪对时间性和事件性前瞻记忆的影响。结果发现,对于背景任务的反应时,在时间性前瞻记忆和事件性前瞻记忆中,情绪的主效应都显著。而对于前瞻任务的正确率,在两种前瞻记忆中,情绪的主效应都不显著。将两个实验的数据合并分析发现,对于前瞻任务的正确率,任务类型的主效应显著,即时间性前瞻记忆的成绩显著高于事件性前瞻记忆; 而情绪的主效应不显著。结果表明,背景任务中不同的情绪刺激会对个体完成背景任务的速度产生影响,而对前瞻记忆任务的执行不会产生影响。     

Age Differences in Multiple Outcome Measures of Time-Based Prospective Memory

ABSTRACT

This study examined time-based prospective memory performance in relation to age, monitoring strategy, response accuracy, and dual-task demands. Young, middle-aged and older adults (N?=?115) completed a prospective memory task, in which they indicated the passing of time every 5 min while listening to a short story (low task demands) or completing a series of cognitive tasks (high task demands). Young and older adults showed similar patterns of monitoring behavior, with low rates of clock checking during the early phase of each 5-min interval, followed by linearly accelerating monitoring functions. However, to obtain the same level of prospective memory performance older adults needed more frequent clock checks than young adults. Furthermore, older adults' compensatory monitoring strategy was associated with an additional cost in primary task performance. Finally, increased primary task demands shifted age differences in prospective memory from monitoring frequency to response accuracy. These findings suggest that goal-directed behavior requires efficient task coordination and resource allocation, and that age-related differences in time-based prospective memory should be evaluated by using multiple outcome measures.     

Comparing time-based and event-based prospective memory over short delays

The current study compared monitoring in time- and event-based prospective memory (PM). Time- and event-based non-focal task instructions were given after a baseline block of a lexical decision ongoing task. Delay between instruction and presentation of PM cue/time was manipulated between-subjects to examine monitoring across short delays (1–6?min). Longer delays decreased performance in the event-based task, but not in the time-based task. This accuracy decline was accompanied by a decline in monitoring (as measured by PM cost to the ongoing task in the trials immediately before the PM cue was presented) between the 1 and 3?min delays. Monitoring was only evident for the time-based task at the 6?min delay as measured by PM cost to the ongoing task. Clock checks were also not affected by delay, but did increase in frequency as the response time neared. These results suggest that delay from the time of intention formation decreases both accuracy and monitoring in event-based tasks, but does not decrease accuracy or monitoring in time-based tasks.     

不同认知方式中小学生的前瞻记忆的研究

以反义词—非反义词判断为进行中任务,探讨了小学、初中和高中的场独立、场依存型各60名学生的前瞻记忆完成情况。结果表明,场独立学生的前瞻记忆成绩明显好于场依存者;小学、初中、高中各年龄组学生的前瞻记忆成绩无明显差异;基于事件的前瞻记忆成绩明显好于基于时间的前瞻记忆。     

Is time-based prospective remembering mediated by self-initiated rehearsals? Role of incidental cues, ongoing activity, age, and motivation

The present research examined self-reported rehearsal processes in naturalistic time-based prospective memory tasks (Study 1 and 2) and compared them with the processes in event-based tasks (Study 3). Participants had to remember to phone the experimenter either at a prearranged time (a time-based task) or after receiving a certain text message (an event-based task) and record the details of occasions when they thought about this intention during a 7-day delay interval. The rehearsal and retrieval of time-based tasks was mediated by more automatic than deliberate self-initiated processes. Moreover, the number of reported rehearsals without any apparent triggers was reliably higher in time- than in event-based tasks. Additional findings concern the effects of age, motivation, and ongoing activities on rehearsal and prospective memory performance.     

Time monitoring and executive functioning in children and adults

This study examined time-based prospective memory performance in relation to individual and developmental differences in executive functioning. School-age children and young adults completed six experimental tasks that tapped three basic components of executive functioning: inhibition, updating, and mental shifting. Monitoring performance was examined in a time-based prospective memory task in which participants indicated the passing of time every 5min while watching a movie. Separate analyses of the executive functioning data yielded a two-factor solution for both age groups, with the updating and inhibition tasks constituting a common factor and the shifting tasks constituting a separate factor. Both children and adults showed accelerating monitoring functions with low rates of clock checking during the early phase of each 5-min interval. However, compared with adults, children needed more clock checks for obtaining the same level of response accuracy. Executive functioning had selective effects on time-based prospective memory performance. In both children and adults, monitoring performance was related to the inhibition and updating components, but not to the shifting component, of executive functioning. We conclude that difficulties in temporary maintenance and updating of working memory contents may create discontinuities in sense of time, leading to an increased reliance on external cues for time keeping.     

Learning is impaired by activated intentions

Two experiments examined the task interference that sometimes accrues from having an intention. In standard prospective memory tasks, latency is often slower to an ongoing task performed concurrently with having an intention than it is when no intention is given. If the locus of this slowing resulted from different attentional allocation policies in the two cases, we predicted that the process of learning a word list would be impaired if participants had an intention rather than if they did not. Four different event-based prospective memory tasks were used in Experiment 1 to demonstrate that worse free recall of a word list resulted when studied with a concurrent intention than with a control condition that had no intention. In that experiment, linking an intention to a distal context that was to occur after learning did not impair free recall. Two time-based tasks were used in Experiment 2 to demonstrate that possessing a time-based prospective memory also hinders learning, unless the intention is linked to a future context that is expected to occur after the study session. In the latter case, no impairment was obtained.     

Varying the importance of a prospective memory task: differential effects across time- and event-based prospective memory

Only few studies have addressed the issue of task importance in prospective memory. Most of them, but not all, have shown that perceived task importance does improve prospective memory performance. However, there is little understanding of (1) the conditions under which importance of the prospective memory task makes a difference in performance and (2) the mechanisms by which perceived task importance has an effect on prospective memory performance. The present study reports two experiments that manipulate task importance in a time-based and an event-based prospective memory paradigm. Results show that importance has an effect on the time-based but not on the event-based task. Further analyses of the performance in the cover tasks as well as the monitoring behaviour indicate that importance improves prospective memory to the degree the task requires the strategic allocation of attentional resources.     

编码方式、认知负荷和线索数量对前瞻记忆的影响

采用2（编码方式：执行意向、练习）×2（认知负荷：高、低）×2（线索数量：单一线索、多线索）的混合设计探讨在不同认知负荷和线索数量下两种编码方式对前瞻记忆的影响。结果表明：认知负荷和编码方式交互作用显著,在高认知负荷条件下,练习编码显著好于执行意向编码;线索数量和编码方式交互作用显著,在多线索条件下,练习编码显著好于执行意向编码。说明执行意向编码更容易受认知负荷和线索数量的影响。研究支持了预备注意与记忆加工理论。     

背景任务刺激间的时距对前瞻干扰效应的影响

前瞻记忆是指形成和保持一个意向直到合适的情境或时间再执行的一种记忆任务。由于在执行背景任务的过程中保持和提取前瞻意向, 使成功执行前瞻记忆任务与加工背景任务之间存在着相互影响。保持前瞻记忆意向对背景任务的反应时和正确率有影响的现象称之为前瞻干扰效应。本研究通过操纵背景任务刺激间时距的两个实验, 考察了背景任务刺激间时距长度对时间性前瞻记忆和事件性前瞻记忆干扰效应量的对比关系的影响。结果发现随着背景任务刺激间时距缩短, 两类前瞻记忆干扰效应量的对比关系发生了变化, 且在背景任务刺激间时距长度不同的情况下执行时间性前瞻记忆任务时, 被试查看时钟的策略也有差异。提示了时间性前瞻记忆任务与事件性前瞻记忆任务认知加工机制上的不同。     

Time-related processes in time-based prospective memory and in time-interval production

Time-based prospective memory tasks require the retrieval of previously formed plans (e.g., call me on my mobile phone) either at a specified time (e.g., at 3 p.m.) or after a specified period of time has elapsed (e.g., in 3 min). In the present study, we investigated whether the same time-related processes are recruited for a short-duration time-based prospective memory task and for a time-interval production task. In a dual-task paradigm, we required young adult participants to make category-membership decisions, while they were simultaneously engaged either in a time-based prospective memory tasks or in a time-interval production task. Under one set of conditions, participants were instructed to allocate attention equally to the two tasks, whereas in another set of conditions, they allocated attention primarily to the time-relevant task. The findings revealed that time estimates were not affected by the attention allocation manipulation, although it influenced performance on the concurrent category membership decision making task, and as expected time estimates were more accurate on the prospective memory task than on the time-production task. Based on the preponderance of the findings, we suggest that timing is managed by different mechanisms and/or strategies on time-interval production tasks and on short-duration time-based prospective memory tasks.     

Age-related differences and complexity of ongoing activities in time- and event-based prospective memory

Aging is presumed to disrupt self-initiated processing, and a time-based prospective memory task (i.e., action to be performed at a particular time) entails more self-initiated activities than an event-based prospective memory task (i.e., action to be performed to a critical event). Accordingly, older participants are predicted to be particularly bad in a time-based prospective memory task. However, the prediction is not always confirmed. Self-initiated activities entail central executive functioning. We therefore predicted the age deficit to emerge more clearly when the performance on the ongoing task also involved more central executive functioning. Time-based prospective memory among older adults collapsed when the complexity of the ongoing task increased. However, an age deficit was also obtained when the pacing of the event-based prospective memory task was high because of the general slowing of functioning by older adults.     

认知方式与线索特征对前瞻记忆的影响

采用实验室研究范式,以汉语双字词为实验材料,探讨了场依存性认知方式、任务类型和线索特征对前瞻记忆的影响。研究结果表明：（1）场独立者的前瞻记忆成绩显著高于场依存者,而回溯记忆成绩没有明显差异;（2）基于事件的前瞻记忆成绩要明显好于基于时间的前瞻记忆成绩。（3）低熟悉性靶线索和与背景有区别的靶线索能促进前瞻记忆的完成,靶线索熟悉性和区别性之间存在非常明显的交互作用。     

Task interference from prospective memories covaries with contextual associations of fulfilling them

One of the current issues in the field of prospective memory concerns whether having an intention produces a cost to other ongoing activities (called task interference). The evidence to date suggests that certain intentions held over the shorter term do interfere with other tasks. Because the cumulative effect of such costs would be prohibitively expensive in everyday life, the present study examined one means by which that interference may be reduced. Participants who formed a specific association to fulfilling an intention in a future context did not exhibit task interference over the intervening period until that context was encountered. This outcome was observed with both an event-based and a time-based prospective memory task. The results suggest that associating intention fulfillment with a specific context can eliminate task interference, and they emphasize the importance of studying intentions that are linked to future contexts versus those that are not.     

Time-based and event-based prospective memory across adulthood: underlying mechanisms and differential costs on the ongoing task

The authors investigated the phenomenon that performance in an ongoing task declines when individuals must carry out a prospective memory (PM) task. This effect is referred to as the PM interference effect. The authors examined whether the PM interference effect differs between event-based and time-based PM tasks and whether it is increased among the elderly. The authors also investigated adult age differences in PM performance and the potential underlying mechanisms of the age deficits in PM. They found that the PM interference effect was greater in event-based than in time-based tasks. However, aging was not associated with an increase in PM interference effects. Age differences in PM performance were more exaggerated in time-based than event-based PM, but they were not mediated by age differences in traditional cognitive ability measures. In time-based PM, age showed a unique adverse effect even after controlling for the ability to externally monitor the time, leading to the possibility that aging disrupts time-based PM because of deficits in internally processing the time.     

Predictors of time-based prospective memory in children

This study identified age differences in time-based prospective memory performance in school-aged children and explored possible cognitive correlates of age-related performance. A total of 56 7- to 12-year-olds performed a prospective memory task in which prospective memory accuracy, ongoing task performance, and time monitoring were assessed. Additional tests of time estimation, working memory, task switching, and planning were performed. Results showed a robust relationship between age and prospective memory performance even after controlling for ongoing task performance. Developmental differences in time monitoring were also observed, with older children generally adopting a more strategic monitoring strategy than younger children. The majority of age-related variance in prospective memory task performance could be explained by cognitive resources, in particular planning and task switching. In contrast, no further independent contribution of time estimation was observed. Findings are in line with the development of strategic behavior, as well as executive functioning, in school-aged children.     

Cognitive control processes underlying time-based prospective memory impairment in individuals with high depressive symptomatology

The current study compared time-based prospective memory (PM) for individuals with high depressive symptomatology (HDS) and low depressive symptomatology (LDS). We examined PM accuracy rate, clock-checking frequency, and decrements in ongoing task performance (i.e., costs to ongoing tasks) associated with an embedded time-based PM task. HDS participants demonstrated numerically lower but statistically comparable clock-checking frequency to LDS participants. However, their PM performance was significantly poorer than that of LDS participants. The pattern of observed costs to ongoing tasks and correlational analyses between ongoing task performance and PM accuracy showed that, relative to LDS participants, HDS participants were restricted in their allocation of attentional resources to support PM. We concluded that although HDS and LDS participants externally controlled their time-based PM task performance (i.e., clock-checking) similarly, the HDS participants lacked the cognitive initiative to allocate attentional resources to internally control PM task performance. Such internal control might reflect time-estimation processes, the resources required to maintain the PM task response intention, and/or the ability to coordinate the PM task response with ongoing task demands. To our knowledge, this is the first paper to have examined time-based PM strategies used by HDS individuals beyond clock-checking. The data suggest that interventions that encourage intermittent strategic reviews of PM goals may be beneficial for individuals with high depressive symptomatology.